Extra charge on prepaid plan

I am using the prepaid plan and total has 4 lines. Based on the prepaid plan, I only need to pay 120 in total, because we select the $35 dollars plan for everyone. The prepaid will deduct 5 dollars which only charge $30 dollars each.

When I looked at my bill, I was charge $139, which is 19 dollars more.

I would like to know what is going on?